What This Tool Does
JSON Web Tokens (JWT) pass authentication claims between clients and servers. Inspecting JWT header algorithms, user roles, permissions, and expiration dates is essential during authentication debugging.
Our JWT Token Decoder decodes JWT strings locally, formatting Header JSON, Payload JSON, and converting UNIX expiration timestamps (`exp`, `iat`) into human-readable date strings without sending tokens across the internet.
How to use
- 1Step 1: Paste encoded JWT string (`eyJ...`) into the token field.
- 2Step 2: Inspect decoded Header JSON and Payload Claims JSON.
- 3Step 3: Review token expiration status and time remaining.
Example Scenarios
Use Case 1:API Debugging: Inspect access token claims during OAuth2 / OIDC development.
Use Case 2:Security Audits: Verify token expiration times and audience scopes.
Why It's Useful
Zero Data Leaks: Tokens stay 100% local in your web browser.
Expiration Watch: Instant visual alert for active vs expired tokens.
Tips for Best Results
Never paste production secret keys on untrusted cloud tools; our tool runs 100% locally.